Insecticidally active nitro guanidine compounds

ABSTRACT

Insecticidally active nitro compounds of the formula ##STR1## wherein R 1  is hydrogen, cyano or alkyl, 
     R 2  is hydrogen or an organic radical, 
     R 3  is --O--R 4 , --S--R 4  or ##STR2## R 4  is an organic radical, R 5  and R 6  are hydrogen or organic radicals, 
     Y is CH or N, and 
     Z is an optionally substituted 5- or 6-membered heterocyclic group, 
     with certain conditions and exceptions.

The present invention relates to novel nitro compounds, to processes fortheir preparation and to their use as insecticides.

It has already been disclosed that a certain group of2-nitro-1,1-ethenediamines is useful as medicaments which influence thecirculation, in particular as hypotensive agents (see the U.S. Pat. No.4,567,188), a certain group of N-cyanoisothioureas is useful asmedicaments for treating ulcers (see Japanese Patent Laid-open No.234,064/1987), the N-cyanoisothioureas disclosed in the above Japanesepatent application have also a function for controlling insects andplant-destructive nematodes (see Japanese Patent Laid-open No. 233,903and EP-A 303,570), and that a certain group of α-unsaturated amines hasinsecticidal/miticidal activity (see EP-A 0302389).

There have now been found novel nitro compounds of the formula (I)##STR3## wherein R¹ is hydrogen, cyano or C₁₋₄ alkyl,

R² is hydrogen, C₁₋₆ alkyl, C₃₋₄ alkenyl, C₃₋₄ alkynyl, C₃₋₈ cycloalkyloptionally substituted by C₁₋₂ alkyl, optionally substituted phenyl,optionally substituted benzyl, C₁₋₄ alkoxy or -(CH₂)_(n) -Z, in which nis 1 or 2 and

Z has the same meaning as stated hereinafter,

R³ is --O--R⁴, --S--R⁴ or ##STR4## in which R⁴ is C₁₋₆ alkyl, C₃₋₄alkenyl, C₃₋₄ alkynyl, C₃₋₈ cycloalkyl, optionally substituted benzyl or-(CH₂)_(n) -Z, in which n has the same meanings as stated above and Zhas the same meanings as stated hereinafter,

R⁵ and R⁶ are the same or different and stand for hydrogen, C₁₋₉ alkyloptionally substituted by at least one substituent selected from thegroup consisting of mercapto, C₁₋₂ alkoxy, C₃₋₆ cycloalkyl, amino, C₁₋₂mono-alkylamino, C₂₋₄ (in total) dialkylamino, C₁₋₂ alkoxy-carbonyl andcyano; or

R⁵ and R⁶ are the same or different and stand for C₃₋₄ alkenyloptionally substituted by halogen, C₃₋₄ alkynyl, optionally substitutedphenyl, optionally substituted benzyl, C₁₋₄ alkoxy, hydroxy, formyl,C₁₋₄ alkylamino, C₂₋₄ (in total) dialkylamino, amino, acyl, 5- or6-membered heterocyclic group optionally substituted by halogen or C₁₋₄alkyl, or --CH₂ --Z in which Z has the same meanings as statedhereinafter, or

R⁵ and R⁶ may form, together with the adjacent nitrogen atom, a 3 to 7membered cyclic group which may be substituted by C₁₋₂ alkyl and mayhave an N, O or S atom as a ring member, besides the adjacent nitrogenatom,

Y is CH or N, and

Z is an optionally substituted 5- or 6-membered heterocyclic group whichhas at least one hetero atom selected from N, O and S and which may bebenzo-fused, provided that where Y is CH, then R¹ is cyano or C₁₋₄alkyl, and with the exception of the case where R¹ and R² are hydrogenor C₁₋₄ alkyl, R³ is --S--R⁴ or ##STR5## in which R⁴ is C₁₋₄ alkyl, R⁵and R⁶ are hydrogen or C₁₋₄ alkyl, Y is CH or N, and Z is 5- or6-membered hetrocyclic group having at least one nitrogen atom which maybe substituted by halogen or C₁₋₄ alkyl.

The compounds of the formula (I) can be obtained by a process in which

a: (in the case where R³ is --S--R⁴ and Y is CH. then R¹ is replaced byR⁷, in which R⁷ is cyano or C₁₋₄ alkyl) compounds of the formula (II)##STR6## wherein R⁴ has the same meaning as mentioned above, are reactedwith compounds of the formula (III) ##STR7## wherein R⁷, R² and Z havethe same meanings as stated above, in the presence of inert solvents, or

b: (in the case where R³ is ##STR8## and Y is CH, then R¹ is replaced byR⁷) ##STR9## wherein R⁷, R², R⁴ and Z have the same meanings asmentioned above,

are reacted with compounds of the formula (IV) ##STR10## wherein R⁵ andR⁶ have the same meanings as mentioned above, in the presence of inertsolvents, or

c: (in the case where R³ is ##STR11## and Y is CH) compounds of theformula (V) wherein R⁴, R⁵ and R⁶ have the same meanings as mentionedabove,

are reacted with the aforementioned compounds of the formula (III) inthe presence of inert solvents, or

d: (in the case where R³ is --S--R⁴ and Y is N) compounds of the formula(VI) ##STR12## wherein R² and R⁴ have the same meanings as mentionedabove, are reacted with compounds of the formula (VII) ##STR13## whereinR¹ and Z have the same meanings as mentioned above, and M is halogen,methanesulfonyloxy or tosyloxy,

in the presence of inert solvents, and if appropriate in the presence ofacid binders, or

e: (in the case where R³ is ##STR14## and Y is N) compounds of theformula (Id) ##STR15## wherein R¹, R², R⁴ and Z have the same meaningsas mentioned above,

are reacted with the aforementioned compounds of the formula (IV) in thepresence of inert solvents, or

f: (in the case where R³ is --O--R⁴ and Y is N) compounds of the formula(VIII) ##STR16## wherein R¹, R², R⁴, Z and M have the same meanings asmentioned above,

are reacted with fuming nitric acid in the presence of concentratedsulfuric acid, and if appropriate in the presence of inert solvents, or

g: (in the case where R³ is --O--R⁴ and Y is CH, then R¹ is replaced byR⁷) compounds of the formula (IX) ##STR17## wherein R⁷, R² and Z havethe same meanings as mentioned above, are reacted with compounds of theformula (X)

    R.sup.4 --OH                                               (X)

wherein R⁴ has the same meaning as mentioned above,

in the presence of inert solvents.

The novel nitro compounds exhibit powerful insecticidal properties.

Surprisingly, the nitro compounds according to the invention exhibit asubstantially greater insecticidal action than those known from theabove cited prior art.

In the formulae, alkyl or the alkyl parts of the mentioned radicals arestraight-chain or branched, and where the alkyl contains 1 to 9 carbons,then it contains preferably 1 to 6, particularly preferably to 4, andwhere the alkyl contains 1 to 6 carbons, then it contains preferably 1to 4, particularly preferably 1 to 3, and where the alkyl contains 1 to4, then it contains preferably 1 to 3, particularly preferably 1 to 2,carbon atoms. As examples there may be mentioned: methyl, ethyl, n- andi-propyl-, n-, i-, s- and t-butyl, n-pentyl, n-hexyl, n-octyl andn-nonyl.

In the formulae, C₃₋₄ alkenyl is 1-propenyl, allyl and 1-, 2- and3-butenyl. Preferred and also particularly preferred is allyl.

In the formulae, C₃₋₄ alkenyl is 1-propynyl, propargyl, 1-butyn-1-yl and2-butyn-1-yl. Preferred and also particularly preferred is propargyl.

In the formulae, C₃₋₈ cycloalkyl contains preferably 3 to 6,particularly preferably cyclohexyl, and C₃₋₆ cycloalkyl is preferablycyclohexyl, and also particularly preferably cyclohexyl.

In the formulae, halogen denotes fluorine, chlorine, bromine and iodine,preferably fluorine, chlorine and bromine, particularly fluorine andchlorine.

In the formulae, phenyl and benzyl described as being optionallysubstituted may contain one or more identical or different substituents.As preferred substituents there may be mentioned halogen such asfluorine, chlorine and bromine, preferably chlorine.

In the formulae, 3 to 7 membered cyclic group is preferably 3 to 6membered cyclic group, particularly preferably pyrrolidino, piperidino2-methylpiperidino, morpholino, piperazino or 1-isoxazolyl.

In the formulae, C₂₋₄ (in total) dialkylamino is preferably and alsoparticularly preferably dimethylamino.

In the formulae, 5- or 6-membered heterocyclic group described as beingoptionally substituted may contain one or more identical or differentsubstituents such as halogen or C₁₋₄ alkyl optionally substituted byhalogen. As examples there may be mentioned: fluorine, chlorine,bromine, idoine, trifluoromethyl, methyl, ethyl, n- and i-propyl, andn-, i-, s- and t-butyl. Preferred and also particularly preferred arechlorine or methyl. The substituent may be in all possible positions ofthe 5-or 6-membered heterocyclic group. Preferably it is in the 6position of the 3-pyridyl ring and in the 2 position of the 5-thiazolylring.

In the formulae, 5- or 6-membered heterocyclic group contains preferablyone or two nitrogen atoms, or one nitrogen atom and either one oxygenatom or one sulfur atom, and said heterocyclic group may be benzo-fused.As preferred examples there may be mentioned: 3-pyridyl, 5-thiazolyl,5-isoxazolyl, 1,2,5-thiadiazol-3-yl, 4-pyrazolyl, 5-oxazolyl,5-pyrimidinyl, and 2-pyrazinyl.

Among the nitro compounds according to the invention, of the formula(I), preferred compounds are those in which

R¹ is hydrogen, methyl, ethyl or n-propyl,

R² is hydrogen, C₁₋₄ alkyl, allyl, propargyl, C₅₋₆ cycloalkyl optionallysubstituted by methyl, phenyl optionally substituted by halogen, benzyloptionally substituted by halogen, C₁₋₃ alkoxy or --CH₂ --Z¹ in which

Z¹ is pyridyl optionally substituted by halogen,

R³ is --O--R⁴, --S--R⁴ or ##STR18## in which R⁴ is C₁₋₄ alkyl, allyl,C₃₋₆ cycloalkyl, phenyl optionally substituted by halogen, benzyloptionally substituted by halogen or --CH₂ --Z¹ in which Z¹ has the samemeaning as stated above,

R⁵ and R⁶ are hydrogen, C₁₋₆ alkyl optionally substituted by at leastone substituent selected from the group consisting of mercapto, methoxy,cyclohexyl, amino, methylamino, dimethylamino, methoxycarbonyl andcyano, allyl optionally substituted by chlorine, propargyl, phenyloptionally substituted by chlorine, benzyl optionally substituted bychlorine, C₁₋₃ alkoxy, hydroxy, formyl, C₁₋₃ alkylamino, dimethylamino,amino, acetyl, benzoyl, 6-chloronicotinoyl, pyridyl optionallysubstituted by chlorine or methyl, or --CH₂ --Z² in which Z² representsthe definition of Z¹ hereinbefore and 5-thiazolyl optionally substitutedby chlorine, in addition R⁵ and R⁶ may form, together with the adjacentnitrogen atom, 3 to 6 membered cyclic group which may be substituted bymethyl and may have an N,O or S atom as a ring member, besides theadjacent nitrogen atom,

Y is CH or N, and

Z is a 5-membered heterocyclic group which has one or two nitrogenatoms, or one nitrogen atom and either one oxygen atom or one sulfuratom and may be substituted by halogen or C₁₋₄ alkyl, or a 6-memberedheterocyclic group which has one or two nitrogen atoms and may besubstituted by halogen or C₁₋₄ alkyl optionally substituted by halogenand said 5- and 6-membered heterocyclic groups may be benzo-fused,provided that where Y is CH, then R¹ is methyl, ethyl or n-propyl, andwith the exception of the case where R¹ is hydrogen, methyl, ethyl orn-propyl, R² is hydrogen or C₁₋₄ alkyl, R³ is --S--R⁴ or ##STR19## inwhich R⁴ is C₁₋₄ alkyl, R⁵ and R⁶ are hydrogen or C₁₋₄ alkyl, Y is CH orN, and Z is 5- or 6-membered heterocyclic group having at least onenitrogen atom which may be substituted by halogen or C₁₋₄ alkyloptionally substituted by halogen.

More preferred nitro compounds of the formula (I) are those in which

R¹ is hydrogen, methyl or ethyl,

R² is hydrogen, methyl, ethyl, n-propyl, allyl, propargyl, cyclohexyl,phenyl optionally substituted by chlorine, benzyl optionally substitutedby chlorine, C₁₋₂ alkoxy or 2-chloro-5-pyridylmethyl,

R³ is ##STR20## in which R⁵ and R⁶ are hydrogen, C₁₋₄ alkyl optionallysubstituted by at least one substituent selected from the groupconsisting of mercapto, methoxy, cyclohexyl, amino, methylamino,dimethylamino, methoxycarbonyl and cyano, allyl optionally substitutedby chlorine, benzyl optionally substituted by chlorine, C₁₋₂ alkoxy,hydroxy, formyl, C₁₋₂ alkylamino, dimethylamino, amino, acetyl, benzoyl,6-chloronicotinoyl, 2-chloro-5-pyridyl, 2-chloro-5-pyridylmethyl or2-chloro-5-thiazolylmethyl, in addition R⁵ and R⁶ may represent,together with the adjacent nitrogen atom, pyrrolidino, piperidino,2-methylpiperidino, morpholino, piperazino or 1-isoxazolyl,

Y is CH or N, and

Z is a 5-membered heterocyclic group which has one or two nitrogenatoms, or one nitrogen atom and either one oxygen atom or one sulfuratom and may be substituted by halogen or C₁₋₂ alkyl optionallysubstituted by fluorine, or a 6-membered heterocyclic group which hasone or two nitrogen atoms and may be substituted by halogen or C₁₋₂alkyl optionally substituted by fluorine, provided that where Y is CH,then R¹ is methyl or ethyl, and with the exception of the case where R¹is hydrogen, methyl or ethyl, R² is hydrogen, methyl, ethyl or n-propyl,

R³ is ##STR21## in which R⁵ and R⁶ are hydrogen or C₁₋₄ alkyl, Y is CHor N, and Z is a 5- or 6-membered heterocyclic group having at least onenitrogen atom which may be substituted by halogen or C₁₋₂ alkyloptionally substituted by fluorine.

Much more preferred nitro compounds of the formula (I) are those inwhich

R¹ is hydrogen, methyl or ethyl,

R² is hydrogen, methyl, ethyl, n-propyl, allyl, propargyl, cyclohexyl,phenyl optionally substituted by chlorine, benzyl optionally substitutedby chlorine, C₁₋₂ alkoxy or 2-chloro-5-pyridylmethyl,

R³ is ##STR22## in which R⁵ and R⁶ are hydrogen, C₁₋₄ alkyl optionallysubstituted by at least one substituent selected from the groupconsisting of mercapto, methoxy, cyclohexyl, amino, methylamino,dimethylamino, methoxycarbonyl and cyano, allyl optionally substitutedby chlorine, benzyl optionally substituted by chlorine, C₁₋₂ alkoxy,hydroxy, formyl, C₁₋₂ alkylamino, dimethylamino, amino, acetyl, benzoyl,6-chloronicotinoyl, 2-chloro-5-pyridyl, 2-chloro-5-pyridylmethyl or2-chloro-5-thiazolylmethyl, in addition R⁵ and R⁶ may represent,together with the adjacent nitrogen atom, pyrrolidino, piperidino,2-methylpiperidino, morpholino, piperazino or 1-isoxazolyl,

Y is CH or N, and

Z is a 5-membered heterocyclic group which has one or two nitrogenatoms, or one nitrogen atom and either one oxygen atom or one sulfuratom and may be substituted by halogen or C₁₋₂ alkyl optionallysubstituted by fluorine, or 6-membered heterocyclic group which has oneor two nitrogen atoms and may be substituted by halogen or C₁₋₂ alkyloptionally substituted by fluorine, provided that where Y is CH, then R¹is methyl or ethyl, and that where R² is hydrogen and R³ is ##STR23## inwhich either R⁵ or R⁶ is hydrogen, the other is allyl, phenyl optionallysubstituted by chlorine, 2-chloro-5-pyridylmethyl or2-chloro-5-thiazolylmethyl, then Y is N, and with the exception of thecase where R¹ is hydrogen, methyl or ethyl, R² is hydrogen, methyl,ethyl or n-propyl,

R³ is ##STR24## in which R⁵ and R⁶ are hydrogen or C₁₋₄ alkyl, Y is CHor N, and Z is a 5- or 6-membered heterocyclic group having at least onenitrogen atom which may be substituted by halogen or C₁₋₂ alkyloptionally substituted by fluorine.

Very particularly preferred nitro compounds of the formula (I) are thosein which

R¹ is hydrogen or methyl

R² is hydrogen, methyl, ethyl, allyl, propargyl, methoxy or2-chloro-5-pyridylmethyl,

R³ is ##STR25## in which R⁵ and R⁶ are hydrogen, C₁₋₂ alkyl optionallysubstituted by at least one substituent selected from the groupconsisting of mercapto, methoxy, cyclohexyl, amino, methylamino,dimethylamino, methoxycarbonyl and cyano, allyl, 2-chloroallyl, benzyl,3- or 4-chlorobenzyl, methoxy, hydroxy, formyl, methyamino,dimethylamino, amino, acetyl, benzoyl, 6-chloronicotinoyl,2-chloro-5-pyridyl or 2-chloro-5-pyridylmethyl,

Y is N, and

Z is 2-chloro-5-pyridyl, with the exception of the case where R¹ ishydrogen or methyl, R² is hydrogen, methyl or ethyl,

R³ is ##STR26## in which R⁵ and R⁶ are hydrogen or C₁₋₂ alkyl, Y is N,and Z is 2-chloro-5-pyridyl.

Specifically, the following compounds may be mentioned:

1-{N-[1-(2-chloro-5-pyridyl)ethyl]-N-methyamino}-1-(2-chloro-5-pyridylmethyl)amino-2-nitroethylene,

1-allyl-3-(2-chloro-5-pyridylmethyl)-2-nitroguanidine, and

1,3-bis-(2-chloro-5-pyridylmethyl)-2-nitroguanidine.

If, for example, in the above process a),1,1-bis-methylthio-2-nitroethylene and1-(2-trifluoromethyl-5-thiazolyl)ethylamine are used as startingmaterials, the course of the reaction can be represented by thefollowing equation: ##STR27##

If, for example, in the above process b),1-[1-(2-chloro-5-pyridyl)ethylamino]-1-methylthio-2-nitroethylene and2-chloro-5-pyridylmethylamine are used as starting materials, the courseof the reaction can be represented by the following equation: ##STR28##

If, for example, in the above process c),1-allylamino-1-methylthio-2-nitroethylene andN-methyl-1-(2-chloro-5-pyridyl)ethylamine are used as startingmaterials, the course of the reaction can be represented by thefollowing equation: ##STR29##

If, for example, in the above process d), 3-nitro-2-methylisothioureaand 5-chloromethyl-2-trifluoromethylpyridine are used as startingmaterials, the course of the reaction can be represented by thefollowing equation: ##STR30##

If, for example, in the above process e),1-(2-chloro-5-pyridylmethyl)-3-nitro-2-methylisothiourea andpropargylamine are used as starting materials, the course of thereaction can be represented by the following equation: ##STR31##

If, for example, in the above process f),1-(2-chloro-5-pyridylmethyl)-2-methlisourea is used as a startingmaterial, the course of the reaction can be represented by the followingequation: ##STR32##

If, for example, in the above process g),1-[1-(2-chloro-5-pyridyl)ethylamino]-1-dimethylamino-2-nitroethylene andethanol are used as starting materials, the course of the reaction canbe represented by the following equation: ##STR33##

In the process a), the compounds of the formula (II) as a startingmaterial mean ones based on the aforementioned definition of R⁴.

In the formula (II), R⁴ preferably has the meaning already given above:

The compounds of the formula (II) include known compounds (see e.g.Chem. Ber., vol. 100, pages 591-604, 1967) and, as an example,1,1-bis-methylthio-2-nitroethylene can be exemplified.

The compounds of the formula (III) as a starting material mean compoundsbased on the aforementioned definitions of R⁷, R² and Z.

In the formula (III), R⁷, R² and Z preferably have the meanings alreadygiven above.

The compounds of the formula (III) include in part known compounds [seeNihon Kagaku Zasshi (Periodical of Japanese Chemistry), vol. 83, pages218-222, 1962, J. Chem. Soc. Perkin I, 1979, pages 2364-2368].

The compounds of the formula (III), for instance, may be prepared inaccordance with a method described in the above reference, J. Chem. Soc.Perkin I, 1979, pages 2364-2368.

The compounds of the formula (III), in case where R² is hydrogen, can beobtained when compounds of the formula (XI) ##STR34## wherein R⁷ and Zhave the same meanings as mentioned above, are hydrolyzed.

The compounds of the formula (XI) can be obtained when Schiff-bases ofthe formula (XII) ##STR35## wherein Z has the same meaning as mentionedabove, are alkylated by reacting with compounds of the formula (XIII)

    R.sup.7 --Hal                                              (XIII)

wherein R⁷ has the same meaning as mentioned above, and Hal is halogen,

in the presence of catalytic amounts of butyl-lithium and in thepresence of an inert solvent such as tetrahydrofuran.

The compounds of the formula (XII) can be obtained when compounds of theformula (XIV)

    Z--CH.sub.2 --NH.sub.2                                     (XIV)

wherein Z has the same meaning as mentioned above,

are reacted with mesitaldehyde in the presence of inert solvents.

The compounds of the formula (XIV) include known ones described in theU.S. Pat. No. 4,499,097, and the aforesaid Nihon Kagaku Zasshi.

In the process b), the compounds of the formula (Ia) as a startingmaterial correspond to a part of the compounds of the formula (I) whichcan be prepared by the above process a).

The compounds of the formula (IV) as a starting material mean ones basedon the aforementioned definitions of R⁵ and R⁶.

In the formula (IV), R⁵ and R⁶ preferably have the meanings alreadygiven above.

The compounds of the formula (IV) are well known in the field of organicchemistry and, as examples, there may be mentioned: methylamine,diethylamine and the like.

In the process c), the compounds of the formula (V) as a startingmaterial mean ones based on the aforementioned definitions of R⁴, R⁵ andR⁶.

In the formula (V), R⁴, R⁵ and R⁶ preferably have the meanings alreadygiven above.

The compounds of the formula (V) can in general be obtained when theaforementioned compounds of the formula (II) are reacted with theaforementioned compounds of the formula (IV).

As examples of the compounds of the formula (V), there may be mentioned:1-allylamino-1-methylthio-2-nitroethylene,1-(2-chloro-5-pyridylmethylamino)-1-methylthio-2-nitroethylene, and thelike.

In the process d), the compounds of the formula (VI) as a startingmaterial mean ones based on the aforementioned definitions of R² and R⁴.

In the formula (VI), R² and R⁴ preferably have the meanings alreadygiven above.

The compounds of the formula (VI) are known (see e.g. J. Am. Chem. Soc.,vol. 76, pages 1877-1879, 1954) and, as examples, there may bementioned: 3-nitro-2-methylisothiourea, 1,2-dimethyl-3-nitroisothiourea,1,1,2-trimethyl-3-nitroisothiourea, and the like.

The compounds of the formula (VII) as a starting material mean thosebased on the aforementioned definitions of R¹, Z and M.

In the formula (VII), R¹ and Z preferably have the meanings alreadygiven above, and M preferably represents chlorine, bromine or tosyloxy.

The compounds of the formula (VII) include known compounds (see JapanesePatent Laid-open Nos. 178,981/1986, 178,982/1986 or 183,271/1986) and,as examples, there may be mentioned:

2-chloro-5-chloromethylpyridine,

2-chloro-5-chloromethylthiazole,

5-chloromethyl-2-trifluoromethylpyridine, and the like.

In the process e), the compounds of the formula (Id) are a part of thecompounds of the formula (I) which can be prepared by the above processd).

In the process f), the compounds of the formula (VIII) as a startingmaterial mean ones based on the aforementioned definitions of R¹, R²,R⁴, Z and M.

In the formula (VIII), R¹, R², R⁴, Z and M preferably have the meaningsalready given above.

The compounds of the formula (VIII) are novel and, in general, can beobtained when compounds of the formula (XV) ##STR36## wherein R¹, R² andZ have the same meanings as mentioned above, are reacted with compoundsof the formula (XIV)

    R.sup.4 --M                                                (XIV)

wherein R⁴ and M have the same meanings as mentioned above.

The above compounds of the formula (XV) in general can be obtained whenthe aforementioned compounds of the formula (III) are reacted with urea.

The above compounds of the formula (XVI) are well-known in the field oforganic chemistry, and as examples there may be mentioned: methyl,ethyl, n-propyl, iso-propyl and 3-pyridylmethyl esters ofp-toluenesulfonic acid, and monochlorides of methane, ethane andpropane, etc.

As examples of the compounds of the formula (XV), there may bementioned: 1-(2-chloro-5-pyridylmethyl)urea,1-(2-chloro-5-thiazolyl)urea, 1-(2-chloro-5-pyridyl)-1-methylurea,1-[1-(2-chloro-5-pyridyl)ethyl]urea, and the like.

As examples of the compounds of the formula (VIII), there may bementioned:

hydrochloride or p-toluenesulfonate of1-(2-chloro-5-pyridylmethyl)-2-methylisourea,

hydrochloride of 1-(2-chloro-5-pyridylmethyl)-2-methylisourea, orp-toluenesulfonate thereof,

hydrochloride of 1-(2-chloro-5-thiazolylmethyl)-2-methylisourea, orp-toluenesulfonate, and the like.

In the process g), the compounds of the formula (IX) as a startingmaterial mean ones based on the aforementioned definitions of R⁷, R² andZ.

The compounds of the formula (IX) are a part of the compounds of theformula (I) which can be prepared by the above process b) or c), and asexamples there may be mentioned:

1-[1-(2-chloro-5-pyridyl)ethylamino]-1-dimethylamino-2-nitroethylene and

1-[1-(2-chloro-5-thiazolyl)ethylamino]-1-dimethylamino-2-nitroethylene.

The compounds of the formula (X) mean ones based on the aforementioneddefinition of R⁴.

In the formula (x), R⁴ has the meaning already given above.

The compounds of the formula (X) are well-known in the field of organicchemistry, and as examples there may be mentioned: methanol, ethanol,propanol, phenol, and the like.

Suitable diluents in the process a) are all inert solvents.

These preferentially include water; aliphatic-, cycloaliphatic- andaromatic- hydrocarbons optionally chlorinated such as hexane,cyclohexane, petroleum ether, ligroin, benzene, toluene, xylene,methylene chloride, chloroform, carbon tetrachloride, ethylene chloride,trichloroethylene, chlorobenzene and the like; ethers such as diethylether, methyl ethyl ether, di-isopropyl ether, dibutyl ether, propyleneoxide, dioxane, tetrahydrofuran and the like; ketones such as acetone,methylethyl ketone, methyl-iso-propyl ketone, methyl-iso-butyl ketone;nitriles such as acetonitrile, propionitrile, acrylonitrile and thelike; alcohols such as methanol, ethanol, iso-propanol, butanol,ethylene glycol and the like; esters such as ethyl acetate, amylacetate; acid amides such as dimethyl formamide, dimethyl acetamide andthe like; and sulfones and sulfoxides such as dimethyl sulfoxide,sulfolane and the like; and bases, for example, such as pyridine.

In the process a), the reaction temperature can be varied within a widerange. In general, the reaction is carried out at a temperature of fromabout 0° C. to 150° C., preferably from about 20° C. to about 90° C.

In general, the reaction is preferably carried out under normalpressure, or also elevated or reduced pressure.

In carrying out the process a), for instance, about 0.9 to slightly morethan one mole of the compounds of the formula (III) may be employed permole of the compounds of the formula (II), and the mixture is reacted inthe presence of inert solvents under heat-reflux until the generation ofmercaptan ceases, so that the desired compounds of the formula (I) canbe obtained.

In carrying out the process b), suitable diluents include the samesolvents as exemplified for the process a).

In the process b), the reaction temperature can be varied within a widerange. For example, the reaction is carried out at a temperature in therange of from about 0° C. to about 150° C., preferably from about 20° C.to about 90° C.

In general, the reaction is preferably carried out under normalpressure, or also elevated or reduced pressure.

In carrying out process b), for instance, equi-molar to slightly morethan one mole of the compounds of the formula (IV) may be employed permole of the compounds of the formula (Ia), and the mixture is reacted inthe presence of inert solvents, so that the desired compounds of theformula (I) can be obtained.

In carrying out the process c), suitable diluents include the samesolvents as exemplified for the process a).

In the process c), the reaction temperature can be varied within a widerange. For example, the reaction is carried out a temperature in therange of from about 0° C. to about 150° C., preferably from about 20° C.to about 90° C.

In general, the reaction is preferably carried out under normalpressure, or also elevated or reduced pressure.

In carrying out process c), for instance, about 0.9 to slightly morethan one mole of the compounds of the formula (III) may be employed permole of the compounds of the formula (V), and the mixture is reacted inthe presence of inert solvents under heat-reflux so that the desiredcompounds of the formula (I) can be obtained.

In carrying out the process d), suitable diluents include the samesolvents as exemplified for the process a).

The process d) may be carried out in the presence of acid binders, suchas hydroxide, hydride, carbonate, bicarbonate and alcoholate alkalimetal, and tertiary amines, for examples, triethylamine anddiethylaniline, and pyridine.

In the process d), the reaction temperature can be varied within a widerange. For example, the reaction is carried out at a temperature in therange of from about 0° C. to boiling point of the reaction mixture,preferably from about 0° C. to about 80° C.

In general, the reaction is preferably carried out under normalpressure, or also elevated or reduced pressure.

In carrying out the process d), for instance, equi-molar to about 1.2mole, preferably equi-molar to about 1.1 mole of the compounds of theformula (VII) may be employed per mole of the compounds of the formula(VI), and the mixture is reacted in the presence of inert solvents, forexample dimethylsulfoxide, and in the presence of a base, sodiumhydride, so that the desired compounds of the formula (I) can beobtained.

In carrying out the process e), suitable diluents include the samesolvents as exemplified for the process a).

In the process e), the reaction temperature can be varied within a widerange. For example, the reaction is carried out at a temperature in therange of from about 0° C. to about 150° C., preferably from about 20° C.to about 90° C.

In general, the reaction is preferably carried out under normalpressure, or also elevated or reduced pressure.

In carrying out the process e), for instance, equi-molar to slightlymore than one mole of the compounds of the formula (IV) may be employedper mole of the compounds of the formula (Id), and the mixture isreacted in the presence of inert solvents, so that the desired compoundsof the formula (I) can be obtained.

In carrying out the process f), for instance, the compounds of theformula (VIII) dissolved in concentrated sulfuric acid are reacted withfuming nitric acid having a purity of higher than 98% at a lowtemperature, preferably at 0° C. or less than 0° C., so that the desiredcompounds of the formula (I) can be obtained.

In carrying out the process g), suitable diluents include the solventsas exemplified for the process a), excluding alcohols.

In the process g), the reaction temperature can be varied within a widerange. For example, the reaction is carried out at a temperature in therange of from about 0° C. to about 120° C., preferably from about 50° C.to about 90° C.

In general, the reaction is preferably carried out under normalpressure, or also elevated or reduced pressure.

In carrying out the process g), for instance, and excess molar amount ofthe compounds of the formula (X) may be employed per mole of thecompounds of the formula (IX), and the mixture is reacted underheat-reflux, so that the desired compounds of the formula (I) can beobtained.

The active compounds are well tolerated by plants, have a favorablelevel of toxicity to warm-blooded animals, and can be used for combatingarthropod pests, especially insects which are encountered inagriculture, in forestry, in the protection of stored products and ofmaterials, and in the hygiene field. They are active against normallysensitive and resistant species and against all or some stages ofdevelopment. The above-mentioned pests include:

from the class of the Isopoda, for example Oniscus Asellus,Armadillidium vulgare and Porcellio scaber;

from the class of the Diplopoda, for example Blaniulus guttulatus;

from the class of the Chilopoda, for example Geophilus carpophagus andScutigera spec.;

from the class of the Symphyla, for example Scutigerella immaculata;

from the order of the Thysanura, for example Lepisma saccharina;

from the order of the Collembola, for example Onychiurus armatus;

from the order of the Orthoptera; for example Blatta orientalis,Periplaneta americana, Leucophaea maderae, Blattella germanica, Achetadomesticus, Gryllotalpa spp., Locusta migrato ria migratorioides,Melanoplus differentialis and Schistocerca gregaria;

from the order of the Dermaptera, for example Forficula auricularia;

from the order of the Isoptera, for example Reticulitermes spp.;

from the order of the Anoplura, for example Phylloxera vastatrix,Pemphiqus spp., Pediculus humanus corporis, Haematopinus spp. andLinognathus spp.;

from the order of the Mallophaga, for example Trichodectes spp. andDamalinea spp.;

from the order of the Thysanoptera, for example Hercinothrips femoralisand Thrips tabaci,

from the order of the Heteroptera, for example Eurygaster spp.,Dysdercus intermedius, Piesma quadrata, Cimex lectularius, Rhodniusprolixus and Triatoma spp.;

from the order of the Homoptera, for example Aleurodes brassicae,Bemisia tabaci, Trialeurodes vaporariorum, Aphis gossypii, Brevicorynebrassicae, Cryptomyzus ribis, Aphis fabae, Doralis pomi, Eriosomalanigerum, Hyalopterus arundinis, Macrosiphum avenae, Myzus spp.,Phorodon humuli, Rhopalosiphum padi, Empoasca spp., Euscelis bilobatus,Nephotettix cincticeps, Lecanium corni, Saissetia oleae, Laodelphaxstriatellus, Nilaparvata lugens, Aonidiella aurantii, Aspidiotushederae, Pseudococcus spp. and Psylla spp.;

from the order of the Lepidoptera, for example Pectinophora gossypiella,Bupalus piniarius, Cheimatobia brumata, Lithocolletis blancardella,Hyponomeuta padella, Plutella maculipennis, Malacosoma neustria,Euproctis chrysorrhoea, Lymantria spp., Bucculatrix thurberiella,Phyllocnistis citrella, Agrotis spp., Euxoa spp., Feltia spp., Eariasinsulana, Heliothis spp., Spodoptera exiqua Mamestra brassicae, Panolisflammea, Prodenia litura, Spodoptera spp., Trichoplusia ni, Carpocapsapomonella, Pieris spp., Chilo spp., Pyrausta nubilalis, Ephestiakuehniella, Galleria mellonella, Cacoecia podana, Capua reticulana,Choristoneura fumiferana, Clysia ambiquella, Homona magnanima andTortrix viridana;

from the order of the Coleoptera, for example Anobium punctatum,Rhizopertha dominica, Acanthoscelides obtectus, Acanthoscelidesobtectus, Hylotrupes bajulus, Agelastica alni, Leptinotarsadecemlineata, Phaedon cochleariae, Diabrotica spp., Psylliodeschrysocephala, Epilachna varivestis, Atomaria spp., Oryzaephilussurinamensis, Anthonomus spp., Sitophilus spp., Otiorrhynchus sulcatus,Cosmopolites sordidus, Ceuthorrhynchus assimilis, Hypera postica,Dermestes spp., Trogoderma spp., Anthrenus spp., Attagenus spp., Lyctusspp., Meligethes aeneus, Ptinus spp., Niptus hololeucus, Gibbiumpsylloides, Tribolium spp., Tenebrio molitor, Agriotes spp., Conoderusspp., Melolontha melolontha, Amphimallon solstitialis and Costelytrazealandica;

from the order of the Hymenoptera for example Diprion spp., Hoplocampaspp., Lasius spp., Monomorium pharaonis and Vespa spp.;

from the order of the Diptera, for example Aedes spp., Anopheles spp.,Culex spp., Drosophila melanogaster, Musca spp., Fannia spp., Calliphoraerythrocephala, Lucilia spp., Chrysomyia spp., Cuterebra spp.,Gastrophilus spp., Hyppobosca spp., Stomoxys spp., Oestrus spp.,Hypoderma spp., Tabanus spp., Tannia spp., Bibio hortulanus, Oscinellafrit, Phorbia spp., Pegomyia hyoscyami, Ceratitis capitata, Dacus oleaeand Tipula paludosa;

from the order of the Siphonaptera, for example Xenopsylla cheopis andCeratophyllus spp.;

from the class of the Arachnida, for example Scorpio maurus andLatrodectus mactans;

from the order of the Arania, for example Acarus siro, Argas spp.,Ornithodoros spp., Dermanyssus gallinae, Eriophyes ribis, Phyllocoptrutaoleivora, Boophilus spp., Rhipicephalus spp., Amblyomma spp., Hyalommaspp., Ixodes spp., Psoroptes spp., Chorioptes spp., Sarcoptes spp.,Tarsonemus spp., Bryobia praetiosa, Panonychus spp. and Tetranychus spp.

The plant-parasitic nematodes include Pratylenchus spp., Radopholussimilis, Ditylenchus dipsaci, Tylenchulus semipenetrans, Heteroderaspp., Meloidogyne spp., Aphelenchoides spp., Longidorus spp., Xiphinemaspp., and Trichodorus spp.

Furthermore, in the field of veterinary medicine, the novel compound ofthe present invention can effectively be employed for combating avariety of noxious animal-parasitic pests (internal- andexternal-parasitic pests), e.g., parasitic insects and nematodes. Suchanimal-parasitic pests may be exemplified as follows:

From the class of insects, e.g., Gastrophilus spp., Stomoxys spp.,Tricodectes spp., Rhodius spp., Ctenocephalides canis and the like.

The active compounds can be converted into the customary formulations,such as solutions, emulsions, wettable powders, suspensions, powders,foams, pastes, granules, aerosols, natural and synthetic materialsimpregnated with active compound, very fine capsules in polymericsubstances, coating compositions for use on seed, and formulations usedwith burning equipment, such as fumigating cartridges, fumigating cansand fumigating coils, as well as ULV cold mist and warm mistformulations.

These formulations can be produced in known manner, for example bymixing the active compounds with extenders, that is to say liquid orliquefied gaseous or solid diluents or carriers, optionally with the useof surface-active agents, that is to say emulsifying agents and/ordispersing agents and/or foam-forming agents. In the case of the use ofwater as an extender, organic solvents can, for example, also be used asauxiliary solvents.

As liquid solvents diluents or carriers, there are suitable in the main,aromatic hydrocarbons, such as xylene, toluene or alkyl napthalenes,chlorinated aromatic or chlorinated aliphatic hydrocarbons, such aschlorobenzenes, chloroethylenes or methylene chloride, aliphatichydrocarbons, such as cyclohexane or paraffins, for example mineral oilfractions, alcohols, such as butanol or glycol as well as their ethersand esters, ketones, such as acetone, methyl ethyl ketone, methylisobutyl ketone or cyclohexanone, or strongly polar solvents, such asdimethylformamide and dimethyl-sulphoxide, as well as water.

By liquefied gaseous diluents or carriers are meant liquids which wouldbe gaseous at normal temperature and under normal pressure, for exampleaerosol propellants, such as halogenated hydrocarbons as well as butane,propane, nitrogen and carbon dioxide.

As solid carriers there may be used ground natural minerals, such askaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceous earth, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates. As solid carriersfor granules there may be used crushed and fractionated natural rockssuch as calcite, marble, pumice, sepiolite and dolomite, as well assynthetic granules of inorganic and organic meals, and granules oforganic material such as sawdust, coconut shells, corn cobs and tobaccostalks.

As emulsifying and/or foam-forming agents there may be used non-ionicand anionic emulsifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycolethers, alkyl sulphonates, alkyl sulphates, aryl sulphonates as well asalbumin hydrolysis products. Dispersing agents include, for example,lignin sulphite waste liquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, can be used in theformulation.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs or metal phthalocyaninedyestuffs, and trace nutrients, such as salts of iron, manganese boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain from 0.1 to 95 percent by weight ofactive compound, preferably from 0.5 to 90 percent by weight.

The active compounds according to the invention can be present in theircommercially available formulations and in the use forms, prepared fromthese formulations, as a mixture with other active compounds, such asinsecticides, baits, sterilising agents, acaricides, nematicides,fungicides, growth-regulating substances or herbicides. The insecticidesinclude, for example, phosphates, carbamates, carboxylates, chlorinatedhydrocarbons, phenylureas, substances produced by microorganisms.

The active compounds according to the invention can furthermore bepresent in their commercially available formulations and in the useforms, prepared from these formulations, as a mixture with synergisticagents. Synergistic agent are compounds which increase the action of theactive compounds, without it being necessary for the synergistic agentadded to be active itself.

The active compound content of the use forms prepared from thecommercially available formulations can vary within wide limits. Theactive compound concentration of the use forms can be from 0.0000001 to100% by weight of active compound, preferably between 0.0001 and 1% byweight.

The compounds are employed in a customary manner appropriate for the useforms.

When used against hygiene pests and pests of stored products, the activecompounds are distinguished by an excellent residual action on wood andclay as well as a good stability to alkali on limed substrates.

The preparation and use of the active compounds according to theinvention can be seen from the following examples.

PREPARATIVE EXAMPLE Example 1 ##STR37##

1-2-(chloro-5-pyridylmethyl)-2-methyl-3-nitroisothiourea (1.0 g) wasdissolved in ethanol (20 ml) and to the solution was added2-chloro-5-aminomethylpyridine (0.55 g) at room temperature, followed byone day stirring at 30° C. The ethanol in the solution was distilled offunder reduced pressure and it was purified on a chromatographic column(the eluent was a mixture of methanol and chloroform) so as to obtainthe desired 1,3-bis-(2-chloro-5-pyridylmethyl)-2-nitroguanidine (1.0 g)having a melting point in the range of from 179° to 182° C.

Referential Example 1 ##STR38##

To a solution of 2-methyl-3-nitroisothiourea (15.0 g) indimethylsulfoxide (100 ml) was gradually added sodium hydride (oil free2.9 g) at 5° C., while being stirred for one hour. Thereafter,2-chloro-5-chloromethyl pyridine (18.0 g) was added to the solution at atemperature in the range of from 5° to 10° C., followed by overnightstirring thereof at room temperature. After the dimethylsulfoxide in thesolution was distilled off under reduced pressure, the resulting residuewas purified on a chromatographic column (the eluent was a mixture ofethanol and chloroform), so as to obtain the desired1-(2-chloro-5-pyridylmethyl)-2-methyl-3-nitroisothiourea (2.0 g) havinga melting point in the range of from 141° to 143° C.

Referential Example 2 ##STR39##

A mixture of 1-(2-chloro-5-pyridyl)ethylamine (4.7 g),1,1-bis-methylthio-2-nitroethylene (5.0 g) and ethanol (50 ml) wasrefluxed under heating until the generation of mercaptan ceased. Then,the ethanol was distilled off from the mixture under reduced pressureand the resulting residue was purified on a chromatographic column (theeluent mixture=ethanol+chloroform) to obtain the desired1-{1-(2-chloro-5-pyridyl)ethylamino}-1-methylthio-2-nitroethylene (3.3g) having a melting point in the range of from 136° to 140° C.

Referential Example 3 ##STR40##

To a solution comprising1-{1-(2-chloro-5-pyridyl)ethylamino}-1-methylthio-2-nitroethylene (2.7g) in ethanol (50 ml) was added dropwise an aqueous solution ofmethylamine (40%, 3 g) at 50° C., followed by two hours stirring at thesame temperature.

Upon cooling the solution to room temperature, the desired product wasseparated in the form of crystals, which were filtered and washed withethanol to obtain the desired1-{1-(2-chloro-5-pyridyl)ethylamino}-1-methylamino-2-nitroethylene (1.5g) having a melting point in the range of from 183° to 186° C.

The compounds of the following formula (I), ##STR41## which can beprepared in the same way as in the above Referential Examples 2 and 3are shown in Table 1.

The compounds of the following formula (I), ##STR42## which can beprepared in the same way as in the above Example 1 and ReferentialExample 1 are shown in Table 2.

                                      TABLE 1                                     __________________________________________________________________________     ##STR43##                                                                    Comp. No.                                                                           Z             R.sup.1                                                                           R.sup.2                                                                          R.sup.3                                            __________________________________________________________________________    1     2-trifluoromethyl-5-thiazolyl                                                               C.sub.3 H.sub.7 -n                                                                H  SC.sub.2 H.sub.5                                   2     2-trifluoromethyl-5-thiazolyl                                                               CH.sub.3                                                                          H  SCH.sub.3                                          3     2-chloro-5-pyridyl                                                                          C.sub.4 H.sub.9 -n                                                                H  NHCH.sub.2 CHCH.sub.2                              4     2-chloro-5-pyridyl                                                                          CH.sub.3                                                                          H  NHCH.sub.2 CHCH.sub.2                              5     2-chloro-5-pyridyl                                                                          CH.sub.3                                                                          CH.sub.3                                                                          ##STR44##                                         6     2-chloro-5-oxazolyl                                                                         CH.sub.3                                                                          H                                                                                 ##STR45##                                         7     2-chloro-5-pyridyl                                                                          CN  H  SCH.sub.3                                          8     2-chloro-5-pyridyl                                                                          CN  CH.sub.3                                                                         SCH.sub.3                                          9     2-chloro-5-pyridyl                                                                          CN  H  NH.sub.2                                           10    2-chloro-5-pyridyl                                                                          CN  CH.sub.3                                                                         NH.sub.2                                           11    2-chloro-5-pyridyl                                                                          CN  H  NHCH.sub.3                                         12    2-chloro-5-pyridyl                                                                          CN  CH.sub.3                                                                         NHCH.sub.3                                         13    2-chloro-5-pyridyl                                                                          CN  CH.sub.3                                                                         N(CH.sub.3).sub.2                                  14    2-chloro-5-pyridyl                                                                          CH.sub.3                                                                          H  OC.sub. 2 H.sub.5                                  __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________     ##STR46##                                                                    Comp. No                                                                            Z              R.sup.1                                                                            R.sup.2      R.sup.3                                __________________________________________________________________________    15    2-trifuoro-methyl-5-pyridyl                                                                  C.sub.2 H.sub.5                                                                    H            SCH.sub.3                              16    2-trifluoro-methyl-5-pyridyl                                                                 C.sub.3 H.sub.7-n                                                                  H            SCH.sub.2 CCH                          17    2,3-dichloro-5-pyridyl                                                                       H    H                                                                                           ##STR47##                             18    3-methyl-5-isoxazolyl                                                                        H    H                                                                                           ##STR48##                             19    2-chloro-5-thiazolyl                                                                         H    C.sub.2 H.sub.5                                                                             ##STR49##                             20    2-chloro-5-thiazolyl                                                                         H    H            OCH.sub.3                              21    2-chloro-5-pyridyl                                                                           H    H            OCH.sub.3                              22    2-chloro-5-pyridyl                                                                           H    CH.sub.3     OCH.sub.3                              23    2-methyl-1,3,4-oxadiazol-5-yl                                                                H    H            OCH.sub.3                              24    1,2,5-thiadiazol-3-yl                                                                        H    H            OCH.sub.3                              25    3-methyl-5-isoxazolyl                                                                        CH.sub.3                                                                           H            OC.sub.2 H.sub.5                       26    2-chloro-5-thiazolyl                                                                         H    H            OC.sub.3 H.sub.7-n                     27    1,2,5-thiadiazol-3-yl                                                                        H    H            OC.sub.3 H.sub.7-iso                   28    2-pyrazinyl    C.sub.3 H.sub.7-n                                                                  H                                                                                           ##STR50##                             29    2-chloro-5-pyridyl                                                                           H    CH.sub.2 CCH NHCH.sub.3                             30    2-cyano-5-pyridyl                                                                            H    CH.sub.3     NHC.sub.2 H.sub.5                      31    2-chloro-5-thiazolyl                                                                         H    H            NHCH.sub.2 CClCH.sub.2                 32    2-methyl-5-pyridyl                                                                           H    CH.sub.3     NHCH.sub.2 CClCH.sub.2                 33    2-chloro-5-pyridyl                                                                           H    H            NHCH.sub.2 CHCH.sub.2                  34    2-chloro-5-pyridyl                                                                           H    CH.sub.3     NHCH.sub.2 CHCH.sub.2                  35    2-methyl-5-pyrazinyl                                                                         H    CH.sub.3     NHCH.sub.2 CHCH.sub.2                  36    2-chloro-5-pyridyl                                                                           H    H            NHCH.sub.2 CCH n.sub.D.sup.50                                                                1.15955                 37    2-chloro-5-pyridyl                                                                           H    CH.sub.3     NHCH.sub.2 CCH                         38    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR51##                             39    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR52##                             40    2-chloro-5-thiazolyl                                                                         H    CH.sub.3                                                                                    ##STR53##                             41    2-methyl-5-pyrazinyl                                                                         H    CH.sub.3                                                                                    ##STR54##                             42    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR55##                             43    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR56##                             44    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR57##                             45    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR58##                             46    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR59##                             47    1,2,5-thiadiazol-3-yl                                                                        H    H                                                                                           ##STR60##                             48    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR61##                             49    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR62##                             50    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR63##     mp.                                                                           179˜182.degree                                                          . C.                    51    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR64##                             52    2,3-dichloro-5-pyridyl                                                                       H                                                                                   ##STR65##    N(CH.sub.3).sub.2                     53    2-cholor-5-pyridyl                                                                           H    CH.sub.2 CCH N(CH.sub.3).sub.2                      54    2,3-dimethyl-5-pryidyl                                                                       H                                                                                   ##STR66##                                                                                  ##STR67##                             55    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR68##                             56    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR69##                             57    2-chloro-5-pyridyl                                                                           H                                                                                   ##STR70##                                                                                  ##STR71##                             58    2-methyl-5-pyrazinyl                                                                         H    H                                                                                           ##STR72##                             59    2-methyl-5-pyridyl                                                                           H    H                                                                                           ##STR73##                             60    2-bromo-5-pyridyl                                                                            H    H                                                                                           ##STR74##                             61    2-chloro-5-pyrimidinyl                                                                       H    H                                                                                           ##STR75##                             62    2-fluoro-5-thiazolyl                                                                         H                                                                                   ##STR76##                                                                                  ##STR77##                             63    1,2,5-oxadiazol-3-yl                                                                         H    H                                                                                           ##STR78##                             64    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR79##     mp.                                                                           169˜172.degree                                                          . C.                    65    2-chloro-5-pyridyl                                                                           CH.sub.3                                                                            ##STR80##                                                                                  ##STR81##                             66    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR82##                             67    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR83##                             68    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR84##                             69    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR85##                             70    2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR86##                             71    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR87##                             72    2-chloro-5-pyridyl                                                                           H    H            NHOCH.sub.3                            73    2-chloro-5-pyridyl                                                                           H    CH.sub.3     NHOCH.sub.3                            74    2-chloro-5-pyridyl                                                                           H    H            N(CH.sub.3)OCH.sub.3                   75    2-chloro-5-pyridyl                                                                           H    CH.sub.3     N(CH.sub.3)OCH.sub.3                   76    2-chloro-5-pyridyl                                                                           H    OCH.sub.3    NH.sub.2                               77    2-chloro-5-pyridyl                                                                           H    OCH.sub.3    NHCH.sub.3                             78    2-chloro-5-pyridyl                                                                           H    OCH.sub.3    N(CH.sub.3).sub.2                      79    2-chloro-5-pyridyl                                                                           H    H            NHNH.sub.2                             80    2-chloro-5-pyridyl                                                                           H    H            NHNHCH.sub.3                           81    2-chloro-5-thiazolyl                                                                         H    H            NHNHCH.sub.3                           82    2-chloro-5-thiazolyl                                                                         H    CH.sub.3     NHN(CH.sub.3).sub.2                    83    2-chloro-5-pyridyl                                                                           H    H            NHOH                                   84    2-chloro-5-pyridyl                                                                           H    CH.sub.3     NHOH                                   85    2-chloro-5-pyridyl                                                                           CN   H            SCH.sub.3                              86    2-methyl-5-pyrazinyl                                                                         CN   CH.sub.3     OC.sub.2 H.sub.5                       87    2-chloro-5-pyridyl                                                                           CN   H            NHCH.sub.3                             88    2-chloro-5-pyridyl                                                                           CN   H            N(CH.sub.3).sub.2                      89    2-chloro-5-pyridyl                                                                           H    H            NHCH.sub.2 CH.sub.2 OC.sub.2                                                  H.sub.5                                90    2-chloro-5-thiazolyl                                                                         H    H            NHCH.sub.2 CH.sub.2 SH                 91    2-chloro-5-pyridyl                                                                           H    H            NHCH.sub.2 CH.sub.2 NH.sub.2           92    2-chloro-5-pyridyl                                                                           H    H            NHCH.sub.2 COOC.sub.2 H.sub.5          93    2-bromo-5-thienyl                                                                            H    CH.sub.3     NH.sub.2       mp.                                                                           159˜161.degree                                                          . C.                    94    2-bromo-5-thienyl                                                                            H    CH.sub.3     NHCH.sub.3                             95    2-bromo-5-thienyl                                                                            H    CH.sub.3     N(CH.sub.3).sub.2                      96    2-bromo-5-thienyl                                                                            H    H            NHCH.sub.3                             97    2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR88##     mp.                                                                           99˜101°                                                           C.                     98    2-chloro-5-pyridyl                                                                           H    H            NHCOCH.sub.3                           99    2-chloro-5-pyridyl                                                                           H    CH.sub.3     NHCOCH.sub.3                           100   2-chloro-5-pyridyl                                                                           H    H                                                                                           ##STR89##                             101   2-chloro-5-pyridyl                                                                           H    CH.sub.3                                                                                    ##STR90##                             __________________________________________________________________________

BIOLOGICAL TESTS ##STR91## Example 5 (Biological Test)

Test on Nephotettix cincticeps having resistance to organophosphorusagents:

Preparation of a test chemical

Solvent: 3 parts by weight of xylene

Emulsifier: 1 part by weight of polyoxyethylene alkyl phenyl ether

To form a suitable preparation, 1 part by weight of the active compoundwas mixed with the aforesaid amount of the solvent containing theaforesaid amount of the emulsifier. The mixture was diluted with waterto a predetermined concentration.

Testing method

Onto rice plants, about 10 cm tall, planted in pots each having adiameter of 12 cm was sprayed 10 ml per pot of the water-dilution ofeach active compound in a predetermined concentration prepared as above.The sprayed chemical was dried, and a wire net having a diameter of 7 cmand a height of 14 cm was put over each pot, and 30 female imagoes ofNephotettix cincticeps showing resistance to organophosphorus agentswere released into the net. The pots were each placed in a constanttemperature chamber and the number of dead insects was examined 2 dayslater, and the Insect mortality was calculated.

As a result, for instance, compound Nos. 36 and 50 showed 100% kill at50 ppm active ingredient.

On the other hand, as comparison, E-1 showed no killing effect at 50 ppma.i.

Example 6 (Biologoical Test)

Test on planthoppers:

Testing method

A water dilution in a predetermined concentration of the active compoundprepared as in Example 5 was sprayed onto rice plants, about 10 cm tall,grown in pots with a diameter of 12 cm in an amount of 10 ml per pot.The sprayed chemical was dried, and a wire net, 7 cm in diameter and 14cm tall, was put over each of the pots. Thirty female imagoes ofNilaparvata lugens Stal of a strain which showed resistance toorganophosphorus chemicals were released into the net. The pots wereleft to stand in a constant temperature chamber and the number of deadinsects was examined two days later. The kill ratio was then calculated.

In the same way as above, the insect mortality was calculated onSogatella furcifera Horvath and organophosphorus-resistant Laodelphaxstriatellus Fallen.

As a result, for instance, compound Nos. 36 and 50 showed 100% kill at50 ppm active ingredient.

On the other hand, as comparison, E-1 showed no killing effect at 50 ppma.i.

It is understood that the specification and examples are illustrativebut not limitative of the present invention and that other embodimentswithin the spirit and scope of the invention will suggest themselves tothose skilled in the art.

We claim:
 1. A nitro compound of the formula ##STR92## wherein R¹ ishydrogen, cyano or C₁₋₄ alkyl,R² is hydrogen, C₁₋₆ alkyl, C₃₋₄ alkenyl,C₃₋₄ alkynyl, C₃₋₈ cycloalkyl optionally substituted by C₁₋₂ alkyl,phenyl optionally substituted by halogen, benzyl optionally substitutedby halogen, C₁₋₄ alkoxy or -(CH₂)_(n) -Z, in which n is 1 or 2, R³ is--O--R⁴, --S--R⁴ or ##STR93## in which R⁴ is C₁₋₆ alkyl, C₃₋₄ alkenyl,C₃₋₄ alkynyl, C₃₋₈ cycloalkyl, phenyl optionally substituted by halogen,benzyl optionally substituted by halogen or -(CH₂)_(n) -Z, R⁵ and R⁶ arethe same or different and stand for hydrogen, C₁₋₉ alkyl optionallysubstituted by at least one substituent selected from the groupconsisting of mercapto, C₁₋₂ alkoxy, C₃₋₆ cycloalkyl, amino, C₁₋₂mono-alkylamino, C₂₋₄ (in total) dialkylamino, C₁₋₂ alkoxy-carbonyl andcyano; or R⁵ and R⁶ are the same or different and stand for C₃₋₄ alkenyloptionally substituted by halogen, C₃₋₄ alkynyl, phenyl, benzyl, C₁₋₄alkoxy, hydroxy, formyl, C₁₋₄ alkylamino, C₂₋₄ (in total) dialkylamino,amino, acyl, 6-chloronicotinoyl, pyridyl optionally substituted bychlorine or methyl, or --CH₂ --Z, or R⁵ and R⁶ may form, together withthe adjacent nitrogen atom, a pyrrolidino, piperidino,2-methylpiperidino, morpholino, piperazino or 1-isoxazolyl group whichmay be substituted by C₁₋₂ alkyl, and Z is a pyridyl, thiazolyl,isoxazolyl, thiadiazolyl, pyrazolyl, oxazolyl, pyrimidinyl or pyrazinylgroup optionally substituted by halogen or C₁₋₄ alkyl with the exceptionof the case where R¹ and R² are hydrogen or C₁₋₄ alkyl, R³ is --S--R⁴ or##STR94## in which R⁴ is C₁₋₄ alkyl, R⁵ and R⁶ are hydrogen or C₁₋₄alkyl, and Z is a 5- or 6-membered heterocyclic group having at leastone nitrogen atom which may be substituted by halogen or C₁₋₄ alkyl. 2.A compound according to claim 1, whereinR¹ is hydrogen, methyl, ethyl orn-propyl, R² is hydrogen, C₁₋₄ alkyl, allyl, propargyl, C₅₋₆ cycloalkyloptionally substituted by methyl, phenyl optionally substituted byhalogen, benzyl optionally substituted by halogen, C₁₋₃ alkoxy or --CH₂--Z¹ in which Z¹ is pyridyl optionally substituted by halogen, R³ is--O--R⁴, --S--R⁴ or ##STR95## in which R⁴ is C₁₋₄ alkyl, allyl, C₃₋₆cycloalkyl, phenyl optionally substituted by halogen, benzyl optionallysubstituted by halogen or --CH₂ --Z¹, and R⁵ and R⁶ are hydrogen, C₁₋₆alkyl optionally substituted by at least one substituent selected fromthe group consisting of mercapto, methoxy, cyclohexyl, amino,methylamino, dimethylamino, methoxycarbonyl and cyano, allyl optionallysubstituted by chlorine, propargyl, phenyl optionally substituted bychlorine, benzyl optionally substituted by chlorine, C₁₋₃ alkoxy,hydroxy, formyl, C₁₋₃ alkylamino, dimethylamino, amino, acetyl, benzoyl,6-chloronicotinoyl, pyridyl optionally substituted by chlorine ormethyl, or --CH₂ --Z² in which Z² represents pyridyl optionallysubstituted by halogen, or 5-thiazolyl optionally substituted bychlorine, or in addition R⁵ and R⁶ may form, together with the adjacentnitrogen atom, a pyrrolidino, piperidino, 2-methylpiperidino,morpholino, piperazino or 1-isoxazolyl group which may be substituted bymethyl.
 3. A compound according to claim 1, whereinR¹ is hydrogen,methyl or ethyl, R² is hydrogen, methyl, ethyl, n-propyl, allyl,propargyl, cyclohexyl, phenyl optionally substituted by chlorine, benzyloptionally substituted by chlorine, C₁₋₂ alkoxy or2-chloro-5-pyridylmethyl, and R³ is ##STR96## in which R⁵ and R⁶ arehydrogen, C₁₋₄ alkyl optionally substituted by at least one substituentselected from the group consisting of mercapto, methoxy, cyclohexyl,amino, methylamino, dimethylamino, methoxycarbonyl and cyano, allyloptionally substituted by chlorine, benzyl optionally substituted bychlorine, C₁₋₂ alkoxy, hydroxy, formyl, C₁₋₂ alkylamino, dimethylamino,amino, acetyl benzoyl, 6-chloronicotinoyl, 2-chloro-5-pyridyl,2-chloro-5-pyridylmethyl or 2-chloro-5-thiazolylmethyl, or in additionR⁵ and R⁶ may represent, together with the adjacent nitrogen atom,pyrrolidino, piperidino, 2-methylpiperidino, morpholino, piperazino or1-isoxazolyl.
 4. A compound according to claim 1, whereinR¹ is hydrogenor methyl R² is hydrogen, methyl, ethyl, allyl, propargyl, methoxy or2-chloro-5-pyridylmethyl, R³ is ##STR97## in which R⁵ and R⁶ arehydrogen, C₁₋₂ alkyl optionally substituted by at least one substituentselected from the group consisting of mercapto, methoxy, cyclohexyl,amino, methylamino, dimethylamino, methoxycarbonyl and cyano, allyl,2-chloroallyl, benzyl, 3- or 4-chlorobenzyl, methoxy, hydroxy, formyl,methyamino, dimethylamino, amino, acetyl, benzoyl, 6-chloronicotinoyl,2-chloro-5-pyridyl or 2-chloro-5-pyridylmethyl, and Z is2-chloro-5-pyridyl.
 5. A compound according to claim 1, wherein suchcompound is 1-allyl-3-(2-chloro-5-pyridylmethyl)-2-nitroguanidine of theformula ##STR98##
 6. An insecticidal composition comprising aninsecticidally effective amount of a compound according to claim 1 and adiluent.
 7. A method of combating insects which comprises applying tosuch insects or to an insect habitat an insecticidally effective amountof a compound according to claim
 1. 8. The method according to claim 7,wherein such compoundis1-allyl-3-(2-chloro-5-pyridylmethyl)-2-nitroguanidine, or1,3-bis-(2-chloro-5-pyridylmethyl)-2-nitroguanidine.